Intaglio press with scraper blade apparatus

ABSTRACT

This intaglio printing press removes surplus ink from the surface of the printing plate in two steps. This invention concerns the first step, in which that surface is scraped with the edge of a flexible blade resiliently engaging the plate and facing in a direction opposite to the direction of cylinder rotation. The plate cylinder has a gap at the ends of each flexible plate. A cam and follower mechanism retracts the blade away from the cylinder when the gap is passing under the blade. Apparatus is provided for retracting the blade away from the cylinder when the ink supply to the plate is interrupted so that the blade will not run against a dry plate. Means are provided to receive and carry away the ink removed from the plate by the blade. The blade is heated and the temperature of the blade is thermostatically controlled to maintain the ink in good flowable condition. The second ink removal step may be a web wiping operation, or a liquid solvent operation, to clean up any residue left by the scraper blade.

Unite States atet DAmato et a1.

[ Apr. 15, 1975 7/1921 United Kingdom 101/157 5/1924 United Kingdom 101/157 [75] Inventors: salvatoreglll TAmato, Flioral'Park; Primary Examiner j Reed Fisher g i oote Attorney, Agent, or FirmCooper, Dunham, Clark,

0t of Griffin & Moran [73] Assignee: American Bank Note Company,

New York, NY. [57] ABSTRACT [22] Fil d; J 15, 1973 This intaglio printing press removes surplus ink from the surface of the printing plate in two steps. This in- 1211 Appl' 370524 vention concerns the first step, in which that surface is scraped with the edge of a flexible blade resiliently en- 52 US. c1 101/157; 101/363 gaging the plate and facing in a direction pp to 51 Int. Cl 1341f 31/02 the direction of cylinder rotation The Plate Cylinder [58] Field of Search 101/157, 169, 152, 153, has a p at the ends Of each flexible P A cam and 101/3 3 350 365 follower mechanism retracts the blade away from the cylinder when the gap is passing under the blade. Ap- 5 References Ci paratus is provided for retracting the blade away from UNITED STATES PATENTS the cylinder when the ink supply to the plate is inter- 38 342 5 191 w d 101 169 rupted so that the blade will not run against a dry 5 8 gg 101x57 plate. Means are provided to receive and carry away 2O76203 W937 Manander' 'm X the ink removed from the plate by the blade. The 12/1943 Grupe 1O1/426 X blade is heated and the temperature of the blade is 2,659305 1 H1953 Giori e e l U 101/155 X thermostatically controlled to maintain the ink in good 3.738.265 6/1973 Saueressig "101/157 flowable condition. The second ink removal step may FOREIGN PATENTS OR APPLICATIONS be a web wiping operation, or a liquid solvent operation, to clean up any residue left by the scraper blade. 581,760 7/1933 Germany l0l/l57 620,074 9/1935 Germany lOl/l57 2 Claims, 6 Drawing Figures 23 4Q 24 O N i a y Z 27 l l 11 \1 43k l 1 1 1 56A 0 55 o 62 Q G e it e G PATENTEDAPR 1 5197s Nb ma PATEEHED 1 1 5 3. 877, 369

sum u [If {a Tic]. r. I l

INTAGLIO PRESS WITH SCRAPER BLADE APPARATUS CROSS-REFERENCES United States patent application Ser. No. 173.555. filed Aug. 20. I971, by Ivaldo Gazzola et al.. entitled Plate Wiping Mechanism for Intaglio Press", now US. Pat. No. 3.762.319, issued Oct. 2, I973. discloses a press using a single step liquid solvent system for removing surplus ink. which may be used as the second surplus ink removal step on a press which uses the system disclosed herein as the first step.

United States patent application Ser. No. 298.443. filed Oct. 17. I972, by Ivaldo Gazzola et al.. entitled Printing Pressure Control Apparatus for Intaglio Press." discloses a press similar to that illustrated herein and with which the present invention may be used.

United States patent application Ser. No. 410,987, filed Oct. 30. I973. entitled Ink Fountain Position Control illustrates an ink supply mechanism which may be used in connection with the present invention.

United States patent application Ser. No. 372.087, filed June 21. 1973. by Salvatore F. DAmato, et al.. entitled Intaglio Printing Press with Web Wiping Apparatus Having Supply and Take-Up Reels Outside Frame. discloses a press using a paper web surplus ink removal system. which may be used as the second surplus ink removal step on a press which uses the system disclosed herein as the first step.

BRIEF SUMMARY OF THE INVENTION The United States Pats. to Rogge et al., No. 2.704.026. and No. Re. 24.161. disclose an ink removal system for a rotogravure press. which is a type of intaglio press. employing a flexible blade which scrapes the surface of the printing plate. The blade resiliently engages the plate and faces in a direction opposite to the cylinder rotation. Presses of the type shown by Rogge et al. employ a plate having a complete cylindrical surface. instead of a flexible plate or plates stretched over a portion of a cylinder between recesses at the ends of the plate.

The present invention employs a similar blade. although it is preferred to use a flat blade rather than a blade of arcuate cross-section such as that shown in the Rogge et al. patent. Since the blade is resilient. and is forcibly pressed against the plate surface to secure an effective scraping action, a problem as to possible in-' terference between the blade and the plate is presented when such a blade is used on an intaglio press having flexible plates with their ends clamped in recesses in the cylinder surface. The present invention provides a cam and follower mechanism for retracting the blade from engagement with the plate when the blade comes opposite the recess in the cylinder. It is preferred to let the blade enter the recess slightly before retracting it. and to have the edge of the blade engage the leading edge of the plate just within the recess, so that any accumulations of ink at the points of first and last contact between the blade and the plate will be within the recess and will not be located where the plate comes in contact with the paper being printed.

The cam which causes retraction of the blade is adjustable so as to accommodate changes in the thickness of the plate being used in the press and for other dimensional changes.

The ink supply mechanism may be interrupted at times. Control means are provided. to ensure that the blade is retracted away from the intaglio plate whenever the ink supply is interrupted to prevent possible scraping of the blade against a dry plate. A heater is provided for the blade, with a thermostatic control to maintain the blade at a temperature at which the ink will flow readily.

A conduit is provided to receive the ink removed by the blade. Most of the ink is removed by the scraper blade, and is in most cases reusable. The scraper blade does not get the plate surface completely clean, however. so that a further more complete cleaning is required. Any suitable apparatus such as a paper wipe apparatus or a liquid solvent apparatus may be used. Such apparatus cleans the ink completely from the plate. but changes the character of the ink so that it is not reusable.

DRAWINGS FIG. 1 is a somewhat diagrammatic elevational view showing the plate cylinder of an intaglio press provided with an ink removing scraper blade in accordance with the invention and also provided with an ink supply system which may be interrupted.

FIG. 2 is a fragmentary view on an enlarged scale, and taken from the opposite side of the press from FIG. 1, with certain parts broken away and others shown in section. illustrating the ink removing scraper blade and its principal supporting parts.

FIG. 3 is a fragmentary sectional view taken along the line 3-3 of FIG. 2.

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3. illustrating the cam and follower structure.

FIG. 5 is a view taken along the line 5-5 of FIG. 3.

FIG. 6 is a view taken along the line 6-6 of FIG. 3.

DETAILED DESCRIPTION A plate cylinder 1 of an intaglio press, which may be a press as described in detail in application Ser. No. 298,443, mentioned above. rotates in a clockwise direction as viewed in FIGS. 1 and 4 and counterclockwise as viewed in FIG. 2. The plate cylinder 1 carries a flexible printing plate 2 having its ends clamped in a suitable recess 1a in the plate cylinder. by means of clamping mechanism shown generally at 3 i and 4. The recess la has entering and leaving edges of long radius, so that the plate 2 is gently curved across those edges.

As the cylinder 1 rotates, its plate 2 is completely covered with ink by an ink supply mechanism generally indicated at 5 and including a steel surfaced ink supply roller 6 forming a part of an ink reservoir generally indicated at 7. The ink supply roller 6 produces a continuous coating of ink on the surface of a transfer roller 8 coated with flexible material, which runs in compressive engagement with the plate 2 on the cylinder 1. The recesses in the plate 2 are thereby filled with ink and the unrecessed surfaces in the plate are also coated with ink. Before making printing contact of the plate 2 with the paper to be printed, it is necessary to remove this coating of ink from the unrecessed surfaces of the plate 2. That removal is accomplished in accordance with the present invention in two steps, the first step being carried out by a scraper blade 11, and the second step by any suitable apparatus, which may be a liquid solvent apparatus as described in US. Pat. No.

I 3,7 62,3 I), mentioned above. or a paper wiping apparatus, as described in application Ser. No. 372,087. also mentioned above.

The ink supply mechanism 5 is shown in detail and claimed in my copending application, Ser. No. 410,987, filed Oct. 30, 1973 mentioned above. The ink supply mechanism 5 is mounted on a carriage l2 shiftable on rails 13 between an ink supplying position, as shown in FIG. 1 and a retracted position in which the rollers 6 and 8 are separated. This movement of the carriage 12 is accomplished by a hydraulic motor 14 having hydraulic fluid supply connections 15 and 16.

The term scraper blade" as used in this specification, is intended to identify a blade whose scraping edge faces in a direction opposite to the rotation of the cylinder being scraped. It is to be distinguished from the more common doctor blade" which faces in the same direction as the cylinder rotation.

The scraper blade 11 is flexible. In its ink removing position, as shown in FIGS. 1, 2 and 4, the blade 1 is resiliently held in engagement with the unrecessed surface of the plate 2, so that its margin near the plate 2 is bent slightly from the general plane of the blade. The opposite margin of the blade is held against a bar 17 by means of a clamp 18, which is in turn held against the bar 17 by means of screws 21. The bar 17 extends the full width of the blade 11, as best seen in FIG. 3. The lower side of the bar 17 is mounted at its ends on a pair of U-shaped yokes 22. The bar 17 is welded to the upper side of one arm of each yoke 22. Each yoke 22 receives between its arms a squared portion 23a of a shaft 23. Each yoke 22 is held on the shaft 23 by means of a hand wheel 24 which is connected to and rotates a screw 25 having an elongated shank 25a provided with a flange 25b and a shoulder 25c spaced from the flange 25b. The threaded portion of screw 25 is threadedly received in an aperture in the squared portion 23a of shaft 23. A protective sleeve 26 encircles the shank 25a and flange 25b, to keep ink from entering the threads of screw 25 and the recess in which it is re- I ceived. A set screw 27 is inserted through one wall of the sleeve 27. The movement of the screw 25 is limited by engagement of set screw 27 with shoulder 250 at one end ofits travel and with flange 25b at the other end, so as to maintain the yoke 22 assembled on the shaft 23. A crank 31 is fixed against rotation with respect to the shaft 23 at its right-hand end as viewed in FIG. 3. The crank 31 is attached by screws 32 to a flange at the end of a sleeve 33 connected by a key 34 to an elongated sleeve 35 having a splined connection to the end of shaft 23. The sleeve 35 has a flange 35a, best seen in FIG. 6, having slots 3512 which rotatably receive screws 36 threaded into a frame member 37 of the press. The screws 36 and the slots 35a limit the rotation of shaft 23 with respect to the frame of the press. The crank 31 rotatably carries at its upper end a roller 41 which cooperates with a cam 42, best seen in FIG. 4. The crank 31 has a downward projection 31a, which is forked to receive a shaft 43. An extension 31b on the lower end of projection 310 extends further downwardly and is connected by a pivot 44 to the end of a piston rod 45 projecting from the cylinder 46 of a hydraulic motor generally indicated at 47. Pivot 44 moves in a slot 310 in the extension 31b so as to provide a lost motion connection. The shaft 43 is supported in a yoke 51 having upstanding arms'5la and 51b. A bearing 52 encircles the right-hand end of shaft 43, as viewed in FIG. 2. The bearing 52 is received in the arm 51a of the yoke. A spring 53 is held in compression between a collar 54 fixed on the shaft 43 and another collar 55 which is loose on the shaft. The collar 55 bears against rounded surfaces on the projection 3114 so that spring 53 biases the projections 31a and shaft 23 for clockwise rotation. as viewed in FIG. 2. This clockwise rotation is opposed by engagement of the edge of the blade 11 with plate 2, and the blade 11 flexes as required to oppose the force of the spring 53. The left-hand end of shaft 43 is threaded. as shown at 43a and cooperates with an internally threaded nut 56, rotatably mounted in the arm 51/) of the yoke 51. The left end of the nut 56 is provided with a hexagonal head 51a. by means of which it may be rotated so as to adjust the compression of the spring 53 and thereby adjust the flexure of the blade 11.

The cam 42 is flxed on the cylinder I adjacent the recess 1a which receives the ends of the plate. The cam 42 has three sections 61, 62 and 63 (FIG. 4). A base plate 64 is attached to the cylinder 1 and supports all three sections. The middle section 62 is fixed on the base plate 64 by means of bolts 65, and is not adjustable. The end sections 61 and 63 are fixed on the base plate 64 by means of screws 66 which extend through slots 61:: and 63a in the end sections 61 and 63, so that those end sections are adjustable circumferentially of the cylinder 1. It is desirable to have the blade 11 reamin in engagement with the plate 2 until just after the blade 11 enters the recess 1a, e.g., until it reaches the point shown at 2a in FIG. 4. Similarly. it is desirable to have the blade engage the plate 2 at a point such as 212 in FIG. 4, just before the end of the recess In. There may be a substantial deposit of ink at the point where the blade first meets the plate 2 and at the point where it leaves the plate 2. By locating these points within the recess 1a, it is ensured that the ink so deposited will not come in contact with the paper being printed, but will remain in the recess 1a where it will not smear the printed sheets.

Note that the cam surface of the middle cam member 62 is of constant radius, so that the blade 11 remains retracted from the cylinder as long as the follower roller 41 is in contact with the middle cam member 62. The cam member 61 is hereinafter termed the rising cam member because it is the first of the three cam members encountered by the follower 41. It has a portion 61b of gradually increasing radius at its left-hand end as viewed in FIG. 4, followed by a constant radius contour portion 610. The radius of the portion 61c is the same as that for the middle cam member 62. The cam member 63, hereinafter termed the falling cam member, has a constant radius portion 63b which is first engaged by the roller 41, followed by aportion 630 of gradually decreasing radius.

In any particular circumferential adjustment of the positions of the cam members 61 and 63, there may be gaps between those members and the middle cam member 62, as shown inFIG. 4. These gaps allow the edge of the blade 11 to drop within the recess 61a. However, the scraping edge of the blade 11 is substantially aligned with the pivot axis of the follower 41. Hence, the locations of the gaps between the cam members is always within the recess 1a, so that the scraping edge of the blade 11 never touches any part of the cylinder 1 or its associated parts because of the presence of the gaps between the cam members.

The hydraulic motor 47 may be actuated by itself to retract the blade 11 from contact with the plate 2. Such an operation of the motor 47 may be produced by actuation of a valve 71 (FIG. I). which is operated by an electromagnet 7141. When electromagnet 71a is deenergized. valve 71 is operated so that motor 47 moves its piston rod 45 to the position shown in FIGS. 1 and 4, and the position of blade 11 is determined by cam 42, follower 41 and spring 53. When electromagnet 71a is energized. valve 71 operates so that motor 47 moves piston rod 45 to the left as shown in FIGS. I and 4, and blade 11 is retracted at least to the dotted line position in FIG. 1, or even farther to the right. Furthermore, the motor 47 is always actuated concurrently with operation of the hydraulic cylinder 14 to interrupt the ink supply to the plate cylinder 1. Cylinder 14 is controlled by a valve 72 operated by an electromagnet 72a. When electromagnet 72a is de-ene rgized, cylinder 14 operates the ink supply mechanism to the position shown in FIG. I, so that ink is supplied to the plate 2. When electromagnet 72a is energized, the ink supply mechanism is shifted to the right to move roller 6 away from roller 8, thereby interrupting the ink supply. Such a concurrent operation of cylinder 14 and of cylinder 37 is accomplished by closure of a switch 81 which completes energizing circuits for both the electromagnets 71a and 72a. When it is desired to operate cylinder 47 only, a switch 82 is actuated to complete an energizing circuit for electromagnet 7141 alone.

The cylinder 47, when actuated, takes up all the lost motion provided by the slot 310 in extension 31b and retracts the blade 11 farther from the cylinder than the retraction produced by the cam means 42. When the cylinder 37 is actuated to restore the piston rod 45 to the position shown in FIG. 4, then either the follower 41 engages the cam 42 or the blade 11 engages and is flexed by the plate 2. In that position of piston rod 45, the cam may move follower 41 through the range of positions permitted by the slot 310, without loading of the cam and follower due to the presence of the cylinder 47. While the retraction of the blade 11 from the plate 2 by the cam and follower is small, it is sufficient to provide the required clearance and to prevent excessive entry of the blade 11 into the recess la.

The bar 17 is provided on the side away from the blade 11 with a channel 75, which catches the ink falling from the surface of the blade 11. The channel 75 has a downwardly depending central portion 7511 (FIG.

3) open at the bottom, which allows the ink collected in the channel 75 to pass downwardly into a suitable receptacle. from which it may be recycled to the ink reservoir 7.

In most cases, the ink removed by the blade 11 is reusable. since it has not been in contact with materials by which it might be absorbed, or which might be absorbed by it. Certain unusual inks, however, have their viscosity or other properties adversely affected by their passage through the ink supply mechanism and over the scraper blade. and cannot be reused.

Thus, the invention in all cases provides a substantial economy of the ink removing material of the final step, e.g., paper or solvent, since less of that material is required to remove the ink residue after the scraping step disclosed herein. Furthermore, in most cases, a substantial economy of the ink itself is provided, since the ink may be reused.

The bar 17 is also provided with an electric heater 76 controlled by a thermostat 77 to heat the bar 17 and thereby the blade 11, to maintain the ink removed from the plate 2 by the blade in a readily fluent condition so that it flows easily through the channel and out through the conduit 75a. The thermostat 77 may be any suitable temperature responsive element, such as a resistance element having a substantial temperature coefficient of resistance. The system by which that element controls the heater 76 may be any suitable system. and should preferably include a manually adjustable resistor by which the temperature maintained by the heater 76 may be selected.

Shaft 23 has fixed thereto a flanged collar 83. Between the flanges of collar 83 rides a finger 84 carried by a lever 85 pivoted at 86 to a mount fixed on a frame member 87 of the press. The lever 85 is oscillated by an eccentric 88 to oscillate the shaft 23 and hence blade 11 endwise as the cylinder 11 rotates. Such oscillation of a scraper or doctor blade assists in its cleaning action and is common in the art.

We claim:

1. An intaglio press comprising:

a. a plate cylinder adapted to support a printing plate having a circumferential length less than the cylinder circumference;

b. an intaglio plate supported on said cylinder and having its ends extending into at least one recess in said cylinder;

c. clamp means in each said recess for holding at least one end of a plate;

(I. a resilient elongated scraper blade;

e. blade supporting means gripping the blade along one longitudinal margin and movable between;

I. an active position in which the longitudinal edge of the blade opposite said margin resiliently engages the plate and faces in a direction opposite to the cylinder rotation; and

2. a range of retracted positions in which said longitudinal edge is spaced from the cylinder periph ery;

f. means biasing the blade supporting means to said active position;

g. means for moving said blade supporting means against said biasing means to said range of retracted positions;

h. said moving means including:

1. cam means rotatable with the cylinder;

2. follower means cooperating with the cam means and connected to the moving means to move the blade supporting means within its range of retracted positions when the blade edge is adjacent a recess in the cylinder;

3. motor means for driving the blade supporting means to retract it against the force of said biasing means; and

4. a lost motion connection between the motor means and the blade supporting means, said motor means being movable between a retracting position in which the lost motion is taken up and the blade is retracted from the plate and an operating position in which the blade supporting means is free of the motor means as long as the blade supporting means is within the range of the lost motion connection, so that the biasing means holds the blade supporting means in its active position and flexes the blade as determined by the force of the biasing means. unless the blade is 3. said lost motion connection being between the separated from the plate by engagement of the motor means and the other of the arms; and cam means with the follower means. i biasing means comprises; P 'mugho press m clam m f l. a second shaft extending through an aperture in a. lsaid tillage supporting means comprises. 5 one of Said arms;

. a s a 7 I t a COll spring encircling said second shaft and a means fixed on the sh [ft for gripping the held between a first collar fixed on the shaft and b. Said moving means Comprises: a second collar loose on the second shaft; and

1. first and second arms fixed to said shaft for con- 10 meims on Smd last f l f arm engagmg the current rotation th with; collar so that the COll spring biases the blade sup- 2. means on one of the arms for supporting the folporting means to its active position.

lower means; 

1. An intaglio press comprising: a. a plate cylinder adapted to support a printing plate having a circumferential length less than the cylinder circumference; b. an intaglio plate supported on said cylinder and having its ends extending into at least one recess in said cylinder; c. clamp means in each said recess for holding at least one end of a plate; d. a resilient elongated scraper blade; e. blade supporting means gripping the blade along one longitudinal margin and movable between;
 1. an active position in which the longitudinal edge of the blade opposite said margin resiliently engages the plate and faces in a direction opposite to the cylinder rotation; and
 2. a range of retracted positions in which said longitudinal edge is spaced from the cylinder periphery; f. means biasing the blade supporting means to said active position; g. means for moving said blade supporting means against said biasing means to said range of retracted positions; h. said moving means including:
 1. cam means rotatable with the cylinder;
 2. follower means cooperating with the cam means and connected to the moving means to move the blade supporting means within its range of retracted positions when the blade edge is adjacent a recess in the cylinder;
 3. motor means for driving the blade supporting means to retract it against the force of said biasing means; and
 4. a lost motion connection between the motor means and the blade supporting means, said motor means being movable between a retracting position in which the lost motion is taken up and the blade is retracted from the plate and an operating position in which the blade supporting means is free of the motor means as long as the blade supporting means is within the range of the lost motion connection, so that the biasing means holds the blade supporting means in its active position and flexes the blade as determined by the force of the biasing means, unless the blade is separated from the plate by engagement of the cam means with the follower means.
 2. a range of retracted positions in which said longitudinal edge is spaced from the cylinder periphery; f. means biasing the blade supporting means to said active position; g. means for moving said blade supporting means against said biasing means to said range of retracted positions; h. said moving means including:
 2. follower means cooperating with the cam means and connected to the moving means to move the blade supporting means within its range of retracted positions when the blade edge is adjacent a recess in the cylinder;
 2. An intaglio press as in claim 1, in which: a. said blade supporting means comprises:
 2. clamp means fixed on the shaft for gripping the blade; b. said moving means comprises:
 2. means on one of the arms for supporting the follower means;
 2. a coil spring encircling said second shaft and held between a first collar fixed on the shaft and a second collar loose on the second shaft; and
 3. means on said last mentioned arm engaging the collar so that the coil spring biases the blade supporting means to its active position.
 3. said lost motion connection being between the motor means and the other of the arms; and c. said biasing means comprises:
 3. motor means for driving the blade supporting means to retract it against the force of said biasing means; and
 4. a lost motion connection between the motor means and the blade supporting means, said motor means being movable between a retracting position in which the lost motion is taken up and the blade is retracted from the plate and an operating position in which the blade supporting means is free of the motor means as long as the blade supporting means is within the range of the lost motion connection, so that the biasing means holds the blade supporting means in its active position and flexes the blade as determined by the force of the biasing means, unless the blade is separated from the plate by engagement of the cam means with the follower means. 